package string;

public class StringBuilderDemo {
    public static void main(String[] args) {
        //StringBuilder的创建方式

        StringBuilder builder1 = new StringBuilder();
        StringBuilder builder2 = new StringBuilder("abc");

        String str = "abc";
        StringBuilder builder3 = new StringBuilder(str); //abc串，基于String对象构造StringBuilder
        String str2 = builder3.toString(); //将builder3转换为String


        StringBuilder builder = new StringBuilder("好好学习java");
        //append():追加内容---在末尾追加
        builder.append("，为了找个好工作");
        System.out.println(builder);  //好好学习java，为了找个好工作
        //replace():替换部分内容(含头不含尾)
        builder.replace(9,16,"就是为了改变世界");
        System.out.println(builder);

        //delete():删除部分内容(含头不含尾)
        builder.delete(0,8);  //删除下标为0到7的
        System.out.println(builder);  //，就是为了改变世界
        //insert():插入内容
        builder.insert(0,"活着");  //在下标0的位置插入活着
        System.out.println(builder);  //活着，就是为了改变世界
    }
}
